Liah_Liah is right, go to icloud.com, they may be still there. If not, try to call Apple. I've read somewhere that they can restore photos that were deleted from iCloud for up to 30 days.
If you have an iTunes backup, you can download some backup extractor app and try to search for these photos. About backing up photos, I think that iCloud is still the best solution if you don't have over 100 GB of photos.